nkh34

Alright so i drive a 97 silverado 1500 with a 5.7l 350 vortec, It is also a 5 speed manual this truck is the one that made me fall in love with chevy and now its acting up and i cant figure it out please help. It idles fine runs good when just driving slow but when you go to get on the gas it lugs down and almost dies before it catches up or i let off the gas. The past few mornings it has also started slow. I live in the mountains in idaho and it has been 20 degrees if we are lucky. So when it started doint this i put in iso heat and filled the tank and drove around to let it get to the lines and it was all the same, so i then replaced the fuel filter i dunno when the last time that was done and nothing changed the fuel pump was replaced in july. It also is NOT throwing a (CEL). So i guess im just looking for other possibilities or any help at all. And Can you still get codes if the CEL isnt on. Thanks for all the help